package com.hb.unic.core.util;

import java.net.InetAddress;

import javax.servlet.http.HttpServletRequest;

import org.springframework.util.StringUtils;

import lombok.extern.slf4j.Slf4j;

/**
 * 获取ip地址工具类
 *
 * @since v1.0，2023/8/26 12:26，create by Mr.Huang.
 */
@Slf4j
public class IpUtils {

    private static final String IP_UTILS_FLAG = ",";
    private static final String UNKNOWN = "unknown";
    private static final String LOCALHOST_IP = "0:0:0:0:0:0:0:1";
    private static final String LOCALHOST_IP1 = "127.0.0.1";

    /**
     * 获取IP公网地址
     * <p>
     * 注意： 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址 如果使用了多级反向代理的话，
     * X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     * </p>
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = "";
        try {
            // 以下两个获取在k8s中，将真实的客户端IP，放到了x-Original-Forwarded-For。
            // 而将WAF的回源地址放到了 x-Forwarded-For了。
            ip = request.getHeader("X-Original-Forwarded-For");
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("X-Forwarded-For");
            }
            // 获取nginx等代理的ip
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("x-forwarded-for");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            // 兼容k8s集群获取ip
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (LOCALHOST_IP1.equalsIgnoreCase(ip) || LOCALHOST_IP.equalsIgnoreCase(ip)) {
                    // 根据网卡取本机配置的IP
                    ip = InetAddress.getLocalHost().getHostAddress();
                }
            }
            // 使用代理，则获取第一个IP地址
            if (!StringUtils.isEmpty(ip) && ip.indexOf(IP_UTILS_FLAG) > 0) {
                ip = ip.substring(0, ip.indexOf(IP_UTILS_FLAG));
            }
        } catch (Exception e) {
            log.warn("Get Ip Error: {}", e.getMessage());
        }
        return ip;
    }

}
